NEW YORK—Actinium Pharmaceuticals Inc., a biopharmaceutical company developing innovative targeted payload immunotherapeutics for the treatment
of advanced cancers, has selected Medpace as its clinical research organization (CRO) for its
pivotal Phase 3 Iomab-B clinical trial. Medpace is a full-service CRO that provides Phase 1-4 core development services for drug, biologic and device
programs.

Dr. Felix Garzon, senior vice president, head of clinical development for Actinium Pharmaceuticals,
said, “We worked extremely diligently to identify the right specialist CRO partner for the pivotal Phase 3 Iomab-B clinical trial, and we are delighted
to announce that we have selected Medpace. Medpace is full-service CRO with a global reach, demonstrated track record of successfully managing clinical
trials and medical and clinical expertise in the field of bone marrow transplantation.”

Although Garzon is
careful not to go beyond noting that it was a complex decision-making process, Medpace seemed the best fit out of a number of CROs Actinium considered.
Experience in transplantation was almost certainly one key factor.

Therapy is part of the transplant
regimen, and must be followed immediately by human cell transplant. New marrow grows back after the transplant and blood production resumes.

The company established an agreement with the U.S. Food and Drug Administration (FDA) that the path to a Biologics License
Application submission for Iomab-B could include a single, pivotal Phase 3 clinical study if it is successful. The population for this two-arm, randomized,
controlled, multicenter trial will be 150 refractory and relapsed acute myeloid leukemia (AML) patients over the age of 55, with 75 patients per arm. The
primary endpoint in the trial is durable complete remission, defined as a complete remission lasting at least six months, and the secondary endpoint will be
overall survival at one year.

There are currently no effective treatments approved by the FDA for AML in this
patient population, and there is no defined standard of care. Iomab-B has completed several physician-sponsored clinical trials examining its potential as a
conditioning regimen prior to human stem cell transplant (HSCT) in various blood cancers, including the Phase 1/2 study in relapsed and/or refractory AML
patients. The results of these studies have demonstrated the potential of Iomab-B to create a new treatment paradigm for bone marrow transplants by expanding
the pool to ineligible patients who do not have any viable treatment options currently, enabling a shorter and safer preparatory interval for HSCT, reducing
post-transplant complications and showing a clear survival benefit including curative potential.

Sandesh Seth,
executive chairman of Actinium Pharmaceuticals, said, “Since receiving clearance of our IND for Iomab-B in December, we have focused on the execution
of our clinical milestones. The selection of Medpace as our CRO is a significant milestone, as it greatly expands our clinical and operational capacities for
the Phase 3 Iomab-B pivotal trial. Iomab-B is the only therapy of its kind and addresses a patient population with significant unmet needs. We remain
steadfastly focused on the execution of this trial with the goal of delivering this much-needed therapy to patients in need of a bone marrow transplant, and
we welcome the addition of Medpace as our partner.”

Iomab-B is a radioimmunoconjugate consisting of BC8, a
novel murine monoclonal antibody, and iodine-131 radioisotope. BC8 has been developed by the Fred Hutchinson Cancer Research Center to target CD45, a pan-
leukocytic antigen widely expressed on white blood cells. This antigen makes BC8 potentially useful in targeting white blood cells in preparation for
hematopoietic stem cell transplantation in a number of blood cancer indications, including AML, chronic myeloid leukemia, acute lymphoblastic leukemia,
chronic lymphocytic leukemia, Hodgkin’s disease, non-Hodgkin lymphomas and multiple myeloma. When labeled with radioactive isotopes, BC8 carries
radioactivity directly to the site of cancerous growth and bone marrow while avoiding effects of radiation on most healthy tissues.